The New Crops Era

Noel Vietmeyer

If the ruler of a distant planet sent you to Earth to assess its plant resources, you'd find that nature's storehouse is truly huge. For example, your initial global inventory would turn up:

3,000 tropical fruits 10,000 grasses

18,000 legumes (members of the family Leguminoseae)

1,500 edible nuts 1,500 edible mushrooms 60,000 medicinal plants

3,000 species with purported contraceptive powers

2,000 plants with pesticidal properties, and

30,000 tropical trees.

Given all that, you'd go back and report to your leader that earthlings are very stupid. Pointing to almost every category of plant resource, you would easily convince him that people have neglected to take advantage of what their planet offers. Were he to colonize earth, you would say, he could do a far better job of managing the place.

In demonstrating where your omnipotent ruler could make vast improvements, you might for instance note that:

Of the 3,000 tropical fruits only fourbanana, mango, pineapple and papayaare produced in any quantity on a global scale.

Of the 10,000 grasses only sevenwheat, rice, maize, barley, sorghum, rye and oatsare employed globally, even though earthlings consider grains from grasses to be "staffs of life," and "foundations of civilization."

Of the 18,000 legumes, only sixpeas, beans, soybeans, peanuts, alfalfa and cloverare used intensively, despite the fact that legumes tend to be remarkably rugged and nutritious plants.

And you would show that only a handful of the nuts, mushrooms, medicinal and contraceptive plants, natural pesticides, and tropical trees are even in research projects.

Turning from the dismal inventory, you would then begin listing the ills of the mismanaged planet: malnutrition, deforestation, desertification, erosion, overpopulation, imbalances of wealth, and others. Finally, with your unbiased vision you would triumphantly demonstrate how your leader could apply the thousands of neglected earth plants to solve such problems.

All that is fantasy of course, but at this time in history we need to step back and look at the earth's resources without our cultural baggage. Many solutions to worldwide problems are on hand if only we earthlings would open our minds to new resources. If another planet used as small a proportion of its natural resources as we do, we would scoff at its lack of vision. Nature offers thousands of potential resources, yet we cling desperately to a handful of plants and animals, most of which were domesticated thousands of years ago by our Stone Age forebears.

Those ancients did a miraculous job considering they had no knowledge of genetics, microorganisms, chemistry, nutrition, or the myriad other sciences vital to success at domesticating and developing crops and livestock. Nor did they have ready access to the variety of germplasm that today we would consider essential for success.

The truth is that we rely on the organisms that were predisposed to easy domestication under primitive conditions. With today's wealth of scientific knowledge and simple communication and transportation, we need no longer be shackled by these limitations. Stone Age science need no longer be the reason for our crop selection. Today, we can build a much wider and ultimately much safer resource base.

In this broader resource base, I'm convinced, lie answers to many of the world's most serious problems. Here are three examples.

Malnutrition. Although the last three decades have seen magnificent increases in world food production and the vast and widely predicted global famines have been staved off, current trends are ominous. Already, maybe as many as a billion children suffer from malnutrition, and billions more will be joining us on the planet in the next three decades. The previous advances have been made with only a handful of well-known cropsmainly wheat, rice, maize, and potato. But these crops are now running out of steam. Annually, the global yield improvements are smaller and smaller and harder and harder to achieve. This is particularly because the good land is almost fully exploited. Future increases in world food production will have to come from sites where our modern pampered crops perform poorly ... from the so-called marginal lands. It is the dry lands, the wet lands, the high lands, the acid-soil lands, and the infertile lands that will have to feed a major part of the world's peoples in the near future.

In these harsh marginal lands, we cannot expect wheat, rice, maize, soybeans and the other well-understood crops to perform outstandingly. However, we can anticipate that the thousands of edible species that are native to such areas can produce new and highly productive food plants.

In our program at the National Research Council, we have reported on a number of promising "new" crops for such situations. These include amaranths (Amaranthus species), bambara groundnut (Voandzeia subterranea), chaya (Cnidoscolus species), jessenia (Jessenia polycarpa), kaniwa (Chenopodium pallidicaule), oca (Oxalis tuberosa), pejibaye (Guilielma gasipaes), pigeon pea (Cajanus cajan), quinoa (Chenopodium quinoa), tepary bean (Phaseolus acutifolius), triticale (x Triticosecale), and winged bean (Psophocarpus tetragonolobus). Hundreds more are to be found in the unlighted comers of nature's storehouse: for instance, in the foods of the Bushmen of the Kalahari, the Aboriginals of Australia, the tribals of India, the Inca's descendants in the high Andes, and peoples throughout the lowland humid tropics.

To take just one example: there are several hundred species of edible leaves hidden away in Africa and other parts of the tropical world. They occur in the zones where malnutrition is most severe, but you won't find detailed discussions of them in the agronomic literature. Thus, given the fact that leafy vegetables are rich in minerals and vitamins and could do much to relieve children's suffering, the world is ignoring one of its most effective ways to overcome malnutrition.

Deforestation. If the planet is to be reforested to a point where tree cover cuts down the global surplus of carbon dioxide and provides an alternative to the raping of the rainforests for wood products, then truly, enormous areas of new forest must be created. The Worldwatch Institute estimates that an additional 320 million acres of treesan area nearly twice the size of Texaswill be needed by the year 2000 to rehabilitate deteriorating ecosystems and to meet the developing countries' growing demands for fuel and industrial wood. Just to offset the burning in the Amazon Basin will require planting tens of millions of trees annually.

At present, the world lacks the range of "botanical tools" necessary for success on such a scale. Commercial tree planting in the tropics is dominated by a mere handful of species: pines, eucalyptus, teak and leucaena. To expect to reforest millions of acres of tropical lands with these few species is to invite disaster. Planting means nothing; survival means everything, and at the moment not many of the new plantings are surviving to become forests.

Yet all is not lost. Foresters have so far sampled only a tiny fraction of the woody members of the plant kingdom. There are perhaps 10,000 potentially useful tropical trees. Almost certainly, the world's best species for reforestation are still awaiting recognition. In our National Research Council program, we have come across several that seem to have enormous promise for regreening the tropics: albizias (Albizia species), alders (Alnus species), bracatinga (Mimosa scabrella), ingas (Inga species), morings (Moringa oleifera), neem (Azadirachra indica), prosopises (Prosopis species), sesbanias (Sesbania species), and tropical acacias (Acacia mangium, A. crassicarpa, and others); not to mention fruit trees, fodder trees, and many "non-trees," including bamboos, cacti, and rattans.

With the need for trees escalating almost by the minute, now is the time to rapidly review the plant kingdom and pick out species that seem most likely to be the "trees of tomorrow." I'm guessing that an explosive increase in tree planting is coming very soon, particularly because corporations and organizations are going to want to plant trees as a way to salve their consciences for releasing tons of carbon dioxide into the air. According to the American Forestry Association, an average tree in an average forest absorbs 13 pounds of carbon dioxide per year. The next time a drought comes through here thousands of farmers and other citizens are likely to head for the local coal-burning utility and industries to force them into growing trees.

Whether tree planting will bring down carbon dioxide levels is almost immaterial: any forests that result will be a very good thing for the world. Cities will become shadier and cooler, eroding slopes will become more stable, and desperate villagers in developing nations will have more chances of getting firewood and the other resources they need to survive.

But all efforts will be wasted unless we have on hand enough species to successfully produce forests in all the myriad latitudes, altitudes, soil types, and rainfall regimes that make up the deforested lands. We need, in my, view, 200 species of trees, and a thousand would be better. We need fast-growing trees, food trees, urban street trees, aluminum tolerant trees, firewood trees, shade trees, timber trees, and forage and utility trees. Most of all, we need extremely resilient, adaptable, stress-resistant species. This is because trees have to go through hell. They look so strong and imperturbable, but they have to remain for years through droughts, winters, pests, hurricanes, fires and other hazards that annual crops seldom have to face. In this regard, trees are one of the most fragile life forms, and for that reason we need an exceptionally large wealth of species in our arsenal of reforestation weapons.

Erosion. Soil erosion is a leading environmental problem all over the world, and is a major drag on economic development in the Third World in particular. Erosion leads to huge losses in farm and forest productivity; it shortens the useful lifetimes of dams, canals, harbors, and irrigation projects; it pollutes wetlands and coral reefs where myriad valuable organisms breed; and it enhances the potential of devastating floods, such as recently occurred in Bangladesh. All in all, soil erosion annually causes multibillion dollar losses to the world economy. And there is no easy remedy for it. In fact, we have so few answers to it that in most places people put erosion out of their minds, as if it were not occurring.

Recently, however, World Bank staff in India have reported that a little-known grass, vetiver (Vetiveria zizanioides), shows great promise as a simple method for halting soil erosion on a wide array of sites. To me, this is one of the most exciting and valuable discoveries of this era.

Vetiver looks somewhat like pampas grass and is native to India, where it is found thriving in the rainforest heat of Kerala, the snows of the Himalayas, and even the deserts of Rajasthan. This deep-rooted plant doesn't normally spread by seed; it propagates itself slowly by vegetative offsets, so it is unlikely to become a pest. Its roots grow almost vertically, and thus don't interfere with nearby crops. It survives in deep shade, burning sands, snows, and is even unaffected by complete immersion in muddy flood waters for at least 40 days.

For erosion control, vetiver is planted in rows across the hillsides, where it merges into tight bands that act like filter cloths and catch anything heading down the slope. The lower parts of its stems are very stiff and are strong enough to hold back a considerable weight of soil, water and debris. In addition, when silt builds up behind it this plant grows higher, just like the grasses planted to build sand dunes. Moreover, it holds back moisture, a vital feature because many tropical areas that get huge amounts of annual rainfall also experience many months of drought each year and that can doom otherwise productive crops and trees.

If this discovery proves successful, I think we'll see hundreds of thousands of miles of vetiver grass strips banding hillsides in every continent. That could produce one of the biggest environmental benefits of this century. Not only will it keep soil out of the rivers and dams and coral reefs, it will raise crop and tree yields at the same time.

I believe that in nature's treasure trove there are many such botanical jewels just waiting for the taking. However, I don't want you to misinterpret the figures. When I state that there are 10,000 grasses. I don't mean that all of them are promising resources. They are not. But we should keep our minds open and dedicate a fraction of the world's agriculture research funds to exploring lesser-known species, seeking out the botanical emeralds and rubies. Out there, awaiting discovery by the visionary and observant researcher, are hundreds of resources of the future including food crops, medicinal crops, tree crops, botanical pesticides, ornamentals, forages and industrial crops. However, for the moment I wish to focus on food crops; compared to the other categories they appeal to everyone.

In food crops, as with other resources, the public tends to be very complacent. This complacency is based on three myths. (1) That we grow the best food crops in the world. (2) That we've grown them forever. (3) That we'll be growing the same ones into the future. Wrong, wrong, and wrong!

Take the first myththe one that says we grow the best food crops in the world. The fact is there are 20,000 plants that have useful edible parts. I exclude species like pine trees, whose underbark is edible, and include only species that have sizable seeds or roots or leaves or stems or flowers or pods that are eaten somewhere in the world. Out of those 20,000 only about a hundred have been brought to an advanced agronomic level. Indeed, its been said that a mere 22 crops feed the world. Wheat, rice and maize by themselves are supposed to provide 50% of the weight of food for the world. This is a tiny, tiny larder from which to feed a planet. It is a dangerous vulnerability. That's why inhabitants of another planet would think us so stupid.

And how did we get these 22 food crops we depend on? Did somebody hold them in the scales, like justice, and select those we have and reject the others? Not so! We have our crops because of the ingenuity and brain-power of our Stone Age forebears. There has been hardly a single food crop domesticated in modern rimes. There are pecans, kiwifruit, wild rice (which is just now being domesticated), blueberry, cranberry, and a few others, but, taken on a global basis, it is a very small number of not very important crops. We cannot say truly that the few score out of the 20,000 species that we eat are the best because there are more than 19,000 that haven't been given a chance.

The second myth is that we've had our food crops always. Most of the public believes that our crops go back to Biblical times or beyond, but most of the foods we eat are remarkably recent arrivals in Western diets. Before the age of Columbus, Europeans lived happily on their few traditional crops: wheat, rye, oats, barley, cabbage and dried peas. They thought that they were eating the best crops, and during their self-righteous complacency they went through famine, many times. This was a common occurrence because when Europe had a cold, wet summer, the wheat, rye, oats and barley wouldn't ripen their grains.

But suddenly, after Columbus, the galleons from Central America and the caravels from South America, brought Europe a cornucopia of new fruits and vegetables: potatoes, sweet potatoes, peanuts, peppers, tomatoes, squashes, beans, maize, pineapple, chocolate, vanilla, not to mention tobacco. These were the traditional foods of the Aztecs, the Incas, the Mayas, and the other American Indians. Europeans had known not one of these before. To them they were revolutionary, not to say subversive, new foods. They resisted them. The tomato was denounced as being toxic. (You can still find a few people who have some doubts about whether it is safe to eat.) The potato was shunned as ungodly because it was not mentioned in the Bible. Many people insisted that potatoes caused leprosy and other dread diseases, and they pointed to Ireland, where there was a population boom, and said that potatoes sent people mad with lust. The truth is, that the Irish children were so well nourished by the potato that they were surviving, whereas in the rest of Europe the children were dying. It actually took decades of study before the English government would officially approve potatoes ... to be eaten by cattle!

But these new foods came to transform European cuisines. Can you imagine Italian food without tomato? Hungarian and Spanish food without paprika? German food without potato? French desserts without vanilla? Switzerland without chocolate? And they transformed diets in other parts of the world, too. Can you imagine Indian, Vietnamese, Thai, Korean, and Szechuan foods without the heat of the chillies? Chillies are native to South America, but had so transformed the Aztec diet in pre-Columbian days that even now most people associate them with Mexico and Mexican food.

Other foods are even more recent newcomers to Western diets. A hundred years ago, Americans had no bananas. At the exposition in 1876 in Philadelphia, bananas were so novel that they were individually wrapped in tinfoil and sold as a novelty for the equivalent of about $2.00 in today's money. It was only at the time of the first World War that the tomato became a major commercial crop in the United States. In the 1920s we didn't have the soybean as an industrial crop. Today, only six decades later, it is our third major crop and the most valuable plant in the whole nation. (At least among those that are legal to grow.) Forty years ago we didn't have broccoli. My information is the first commercial field of broccoli was planted in 1947. Now, it's supposed to be the fastest increasing vegetable in the country. So you can see that we certainly haven't had our crops forever, and most of the foods we now eat regularly were "new crops" just "yesterday."

Turning now from looking backwards to looking forwards, there is the myth that we will cultivate in the future the same crops that we cultivate today. This, too, is false and the evidence is all around us. Today, we are eating vegetables, fruits, spices that were unknown to previous generations of Americans. Examples include garbanzo beans, chillies, avocados, artichokes, beansprouts, snowpeas, shiitaki mushrooms, tofu, and jicama. These and dozens of other exotic foods are becoming as American as pizza, apple pie (which came from England), hamburger and tacos. And many more are coming.

In the last ten years the average number of different items carried by the produce departments in supermarkets nationwide has doubled; rising from 65 to more than 140. Some stores are annually carrying more than 400 different fruits and vegetables. Specialty produce has become a booming, hundred million dollar a year, business. Indeed, the supermarketing industry has found that ten years ago people chose a supermarket on the basis of the meat department and on the quality of the meat, but today, they choose their store on the basis of the produce department and on the variety it carries.

I make these points to counter those who oppose new food crops on the basis that "there's no future in them." In fact, for the development of new food crops we are very lucky right now. We've got many new ethnic groups: Vietnamese, Chinese, Japanese, Thais, Filipinos, Cubans, West Indians, and Salvadorans, for example. All are demanding the crops and varieties and tastes of home. Adventurous plantsmen are responding to this. For example, South Florida, the most horticulturally dynamic area in the world, has more than 10,000 acres of Latino and Asian fruits and vegetables: boniato, malanga, calabaza, yuca, pigeon peas, annonas, and mamey. Just as the Italians' pizza spread out into the rest of the American diets, so too will these foods of Asia and Lain America. These are the components of tomorrow's meals.

For anybody interested in developing new food crops, this is the best time in history. In a sense, United States is leading humankind into a global cuisine in which the whole world's diversity will be available to all. For the first time in history people will be able to sample hundreds, maybe thousands, of the edible plants that the planet offers. For the first time, people everywhere will be able, like justice, to hold up the scales and measure which are the "best" food crops for them. No longer will Stone Age capabilities dictate what we eat. And we'll be able to adapt scores of new tastes and textures, shapes and colors to our culinary styles, as we have with pizza, potatoes and the other forerunners.

When you add this dynamism in food crops to the rising concern over global environmental ills, you can see that we're entering the era of "new crops " Not only will this new era help solve many global problems, but it will provide the U.S. with dozens of new resources, as well as a new agricultural vitality, and a wealth of entrepreneurial opportunities.